The present invention relates to ballistic armor systems, more particularly to composite ballistic armor systems that include a metallic matrix and one or more metallic or non-metallic elements contained therein.
Military armor applications include land, air and sea vehicles, stationary structures, and personnel. The need for lighter weight and more effective armor plating for protecting various military vehicles is ongoing, especially as enemy munitions become increasingly powerful. Protection of the vehicles and their occupants is needed against impact by a projectile such as a ballistic body (e.g., small arms fire) or an explosive fragment (e.g., shrapnel from a bomb blast). Conventional metal vehicle armor systems basically consist of metal alloy plates, principally steel. These conventional armor systems are becoming prohibitively heavy in order to protect vehicles from increasingly formidable attack capabilities.
A metal matrix composite (MMC) material is a composite material having a metallic matrix and one or more elements, metallic or non-metallic, contained in the metallic matrix. One approach that has been considered for constructing an armor system that is both strong and lightweight involves the utilization of one or more hard solid elements and a relatively lightweight metallic material (elemental metal or metal alloy) as a matrix material for containing the elements. Generally speaking, according to the theory of operation of a metal matrix composite armor system, an element or elements contained in a metallic matrix serve to absorb the energy of an impinging projectile by dissipating the energy into a volume surrounding the penetration point.
For instance, hard spheres (e.g., ceramic spheres of uniform size) have been considered for embedment within a lightweight metal such as an aluminum alloy. For optimal efficiency of energy dissipation of an impinging projectile, the embedded spheres should be arranged in a regular array so that the spheres are not in contact with each other, and so that there is a good bond between the spheres and the metal matrix. Fabrication of a metal matrix composite armor system containing spherical elements has been problematical insofar as achieving these objectives.
Aluminum oxide (commonly called “alumina”), silicon carbide, boron carbide, and titanium carbide are ceramic materials that are known to be suitable for armor applications. These conventional armor ceramics have been used in conventional practice of armor systems.